Modern medical practices require the application of a sheath to the tip of conventional medical probes, such as ultra sound, rectal or vaginal probes, prior to insertion of such probes into the body of a patient. Moreover, investigatory medical probes are often used to penetrate the body through a wound to discern the healing status of open tissue. Such medical practices normally require utilization of a non-latex sheath since the sheath may contact blood or other body fluids in which latex has been found to cause infection or an allergic reaction.
Application of the sheath to the probe is normally preceded by injection of a suitable moisturizing gel into the nose of the sheath. This gel further enhances the optical or ultra sound coupling between the active end of the probe tip and the sheath to enhance the quality of medical data gathered upon insertion into the body.
Prior art devices have normally involved the mounting of a fully extended sheath onto a carrier. In order to extend the probe into the entire length of the sheath, the medical technician or doctor will insert the probe through the sheath opening and slowly manipulate the tip of the probe such that it travels through the sheath length to its nose. This process can result in inadvertent contact with the wall of the sheath which will engage or become in direct contact with the patient. Moreover, it is difficult to inject the transmission gel into the nose of a fully extended sheath since such gel must travel the entire length of the sheath to be deposited proximate the subsequent placement of the active end of the probe tip.
Typical prior art devices are disclosed in the following U.S. Patents:
U.S. Pat. No. Inventor(s) Issue Date 4,062,239 C. F. Fowler, et al. Dec 13, 1977 4,165,000 G. W. Poncy Aug. 21, 1979 4,197,944 D. G. Catlin Apr. 15, 1980 4,614,442 G. W. Poncy Sept. 30, 1986 4,684,018 E. Jarund Aug. 4, 1987 4,823,949 H. Bala Apr. 25, 1989 5,069,337 H. Bala Dec. 3, 1991
Of these devices, that disclosed by Fowler, et al. ('239) is a probe cover incorporating an inner sheath with a probe end engagement section which defines a reduced width at the distal end thereof. The reduced width is formed by a non-permanent bonding of the sheath layers using a graduated strength bond.
Poncy ('000) discloses a sterile sheath carried on a substrate having a tear tab. Poncy does not disclose an inverted portion of the sheath. The sheathes disclosed by Bala ('337 and '949), Jarund ('018) and Poncy ('442) are similar in constriction to the '000 device.
The '944 device disclosed by Catlin is defined by two sheaths disposed in an end to end fashion, with the probe being inserted into a smaller of the two, and the larger of the two then being inverted over the first. The probe is thus disposed within two sheathes once completely inserted.
Accordingly, it is an object of the present invention to provide a tubular sheath having an inverted nose releasably mounted on a carrier such that the tip of a probe can be readily inserted into the nose as the balance of the length of the sheath is moved about the probe length. Another object of the present invention is to provide such a sheath with an inverted nose that shields the surface of the sheath wall which contacts the patient upon insertion of the probe into the patient's body, such that inadvertent contact with this sheath surface on the patient side is reduced as the sheath is placed over the medical probe.
Other objects and advantages of the invention over the prior art will become apparent to those skilled in the art upon reading the detailed description together with the drawings which are described below.